Building and Installing

The first step is to install the binary distribution. I followed
the Slackwiki’s instructions to create a package which
I could easily remove later. I then installed it, using installpkg
as root.

Next, You need to put the cabal-install program (which is actually
just cabal) somewhere in Your path. I have a directory
~/bins/bin/ where I put all binaries I use on a general basis,
that I don’t need to be installed system wide. Setting that up will
probably be the topic of another post, which (if and when it is
written) I will link to here.

Now that Your build environment is set up, You can extract the
haskell-platform file into a new directory, cd into it, and run
the following command: ./platform.sh <Bindist Tarball>. Replace
‘‘ with the path to Your previously downloaded
binary distribution tarball. For instance, I use an x86 distro, and
so mine was: ./platform.sh
~/Downloads/ghc-7.8.3-i386-unknown-linux-centos65.tar.xz.

When that command finishes (it takes a while), You’ll have a new
tarball in the ./build/product/ directory. As a good sysadmin,
You should take the time to untar it into its own directory, add a
slack-desc, and package it up. Then, remove the binary
distribution package, and take cabal out of Your path.

Now, simply run (as root): installpkg haskell_platform.txz. Once
it installs, the last bit of set up is to run the following
program: /usr/local/bin/activate-hs.

Cabal and Pandoc

To take Your newly installed Haskell and install pandoc, it is really
as simple as: cabal install pandoc. Once that finishes, You will
have pandoc fully available to You.

But, as others have said, Cabal is not a Package
Manager. Upgrading Pandoc will not be elegant, and uninstalling it
will have to be manual, as cabal-install does not handle either of
those two things well (or at all, really).